• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.3
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• pp.545-550
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• 2018

Ultra-lightweight block cipher CHAM, consisting of simple addition, rotation, and eXclusive-or operations, enables the efficient implementations over both low-end and high-end Internet of Things (IoT) platforms. In particular, the CHAM block cipher targets the enhanced computational performance for the low-end IoT platforms. In this paper, we introduce the efficient implementation techniques to minimize the memory consumption and optimize the execution timing over 8-bit AVR IoT platforms. To achieve the higher performance, we exploit the partly iterated expression and arrange the memory alignment. Furthermore, we exploit the optimal number of register and data update. Finally, we achieve the high RANK parameters including 29.9, 18.0, and 13.4 for CHAM 64/128, 128/128, and 128/256, respectively. These are the best implementation results in existing block ciphers.

• Steel and Composite Structures
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• v.22 no.5
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• pp.1085-1114
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• 2016

This paper investigates the transverse impact response for ultra lightweight cement composite (ULCC) filled pipe-in-pipe structures through a parametric study using both a validated finite element procedure and a validated theoretical model. The parametric study explores the effect of the impact loading conditions (including the impact velocity and the indenter shape), the geometric properties (including the pipe length and the dimensions of the three material layers) as well as the material properties (including the material properties of the steel pipes and the filler materials) on the impact response of the pipe-in-pipe composite structures. The global impact responses predicted by the FE procedure and by the theoretical model agree with each other closely. The parametric study using the theoretical approach indicates the close relationships among the global impact responses (including the maximum impact force and the maximum global displacement) in specimens with the equivalent thicknesses, proposed in the theoretical model, for the pipe-in-pipe composite structures. In the pipe-in-pipe composite structure, the inner steel pipe, together with the outer steel pipe, imposes a strong confinement on the infilled cement composite and enhances significantly the composite action, leading to improved impact resistance, small global and local deformations.

• Journal of Advanced Technology Convergence
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• v.2 no.2
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• pp.9-14
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• 2023

This study is shown the result of the first year to develop an export 1050MPa-class lightweight ductile iron castings Austempered control arm through the research process to obtain the following results. First, the structure of the optimal design Layout design and development of the component, and then achieve them through the Control Arm rigidity and optimal structure design and robust design of the focus areas of the expected stress Control Arm. Second, to develop a Control Arm reflects the high rigidity and high performance lightweight structures. Control Arm them developed to meet the design and rigidity as required by the consumer through the hollow, and to develop a process for the Core. Third, through optimum alloy composition and heat treatment methods will be derived to derive the amount of iron alloy (Cu, Ni, Mo) and Austempered heat treated and tempered condition. Fourth, through the development of optimum molding technology development component to develop the optimum ADI for the low-stiffness, high-rigidity component development, it attempts to develop a high-strength casting forming technology..

• Journal of electromagnetic engineering and science
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• v.18 no.3
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• pp.188-198
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• 2018

In this study, we propose an approach for the design and satisfy the requirements of the fabrication of a small, lightweight, reliable, and stable ultra-wideband receiver for millimeter-wave bands and the contents of the approach. In this paper, we designed and fabricated a stable receiver with having low noise figure, flat gain characteristics, and low noise characteristics, suitable for millimeter-wave bands. The method uses the chip-and-wire process for the assembly and operation of a bare MMIC device. In order to compensate for the mismatch between the components used in the receiver, an amplifier, mixer, multiplier, and filter suitable for wideband frequency characteristics were designed and applied to the receiver. To improve the low frequency and narrow bandwidth of existing products, mathematical modeling of the wideband receiver was performed and based on this spurious signals generated from complex local oscillation signals were designed so as not to affect the RF path. In the ultra-wideband receiver, the gain was between 22.2 dB and 28.5 dB at Band A (input frequency, 18-26 GHz) with a flatness of approximately 6.3 dB, while the gain was between 21.9 dB and 26.0 dB at Band B (input frequency, 26-40 GHz) with a flatness of approximately 4.1 dB. The measured value of the noise figure at Band A was 7.92 dB and the maximum value of noise figure, measured at Band B was 8.58 dB. The leakage signal of the local oscillator (LO) was -97.3 dBm and -90 dBm at the 33 GHz and 44 GHz path, respectively. Measurement was made at the 15 GHz IF output of band A (LO, 33 GHz) and the suppression characteristic obtained through the measurement was approximately 30 dBc.

• Design & Manufacturing
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• v.12 no.2
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• pp.34-39
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• 2018

The biggest topics in the automobile industry are light weightening and fuel efficiency improvement. There's a lot of research going on. It is focused on light weight materials. Light weight material is seen as the best way to reduce fuel consumption and to solve the problem of environmental pollution and resource depletion. For the light weight materials, new materials such as aluminum, magnesium, and carbon-hardening materials can be found. Research on the joining techniques of dual materials, improvement of material properties by improving the method of manufacture of existing materials, and studies on ultra-high strength steel sheets are expected to take up the most weight in lightweight materials. As the strength of the ultra-high strength steel sheets increases during forming, it is difficult to obtain dimensional precision due to the increase in elastic restoring force compared to mild or high strength steel sheets. Spring back is known to be affected by a number of factors due to poor plastic molding, and can be divided into the effects of the material spraying and the process. The study on the plasticitic variables were studied as plasticitic factors that can be controlled by a part company. Tensile testing of ultra-high strength materials was conducted to derive properties for plasticitic analysis and to analyze spring back with two factors controlling the height of the bead and blank holding force by adding tensile force and controlling the flow rate.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.3
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• pp.277-286
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• 2001

Among the ULSAB methods for the lightweight automobile body, Tailor Welded Blank(TWB) is adopted and the design process is developed for the existing component. Topology optimization conducted to find the distribution of the variable thickness. The number of parts and the welding lines are determined from it. In the detail design, size optimization is carried out to find the optimum thickness of each part and then, the final parting lines are tuned by shape optimization. A commercial optimization software GENESIS is utilized for the optimization processes.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.5
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• pp.107-112
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• 2020

Ultra-lightweight password CHAM is an algorithm with efficient addition, rotation and XOR operations on resource constrained devices. CHAM shows high computational performance, especially on IoT platforms. However, lightweight block encryption algorithms used on the Internet of Things may be vulnerable to side channel analysis. In this paper, we demonstrate the vulnerability to side channel attack by attempting a first power analysis attack against CHAM. In addition, a safe algorithm was proposed and implemented by applying a masking technique to safely defend the attack. This implementation implements an efficient and secure CHAM block cipher using the instruction set of an 8-bit AVR processor.

• Composites Research
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• v.22 no.6
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• pp.52-62
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• 2009

This paper is for the state of the art of the lightweight protective clothing against the mine, and it covers the preliminary work focused on the appropriate protection, ballistics, convenience, and wearability. It is suggested that the lightweight protective clothing should be fabricated with the laminated materials of high strength woven and non-woven fabrics to reduce the weight and thickness, thus improving the wearability. And partial reinforcement of the protective clothing is necessary to prevent the mortal wound near the important parts of the body without disturbing the arbitrary activity. The composition of the protective clothing should be designed in consideration of easy putting-on and taking-off in addition to easy divesture, which require little motion of the body is in case of serious injury. Additionally, status of the practical technique for high performance and ultra-light hybrid armor material were also described.

• Journal of IKEEE
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• v.27 no.4
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• pp.524-530
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• 2023

This paper proposes an efficient algorithm to detect CAN (Controller Area Network) bus attack based on a lightweight CNN (Convolutional Neural Network), and an IDS(Intrusion Detection System) was designed, implemented, and verified with FPGA. Compared to conventional CNN-based IDS, the proposed IDS detects CAN bus attack on a frame-by-frame basis, enabling accurate and rapid response. Furthermore, the proposed IDS can significantly reduce hardware since it exploits only one convolutional layer, compared to conventional CNN-based IDS. Simulation and implementation results show that the proposed IDS effectively detects various attacks on the CAN bus.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.3
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• pp.283-288
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• 2012

Ultra-high-strength steels (UHSSs) are widely used for lightweight automobile parts, and the control of springback is very important in sheet-metal forming. The object of this study is to verify the effects of multi-stage forming process parameters for U-channel-type automobile parts made of UHSS. Finite element analysis is carried out to predict the formability and springback. The main parameters considered for the multi-stage forming process are the die angle, die radius, and punch-forming direction. It is shown that multi-stage forming is very effective for reducing springback, and that a small punch-forming angle and die radius reduce springback, whereas the die angle does not have a large effect.